新疆卡特巴阿苏金铜矿床地质特征及其控矿因素

Geological Characteristics and Ore-controlling Factors of Kateba’asu Au-Cu Deposit in Xinjiang

卡特巴阿苏金铜矿床是新疆西天山近年来发现的特大型金铜矿床之一,前人关于该矿床地质特征及成矿过程系统研究较少。笔者对卡特巴阿苏金铜矿床矿体产出特征、矿石矿物组成及结构构造、围岩蚀变、成矿作用期次等进行了研究,对矿床的控矿因素进行了分析。通过对矿床地质特征研究,并结合岩矿分析结果,认为矿体主要产于二长花岗岩中,受破碎带节理构造系统及岩体与大理岩地层接触带的控制。节理系统中矿体为脉带状,矿石主要为细脉状、细脉浸染状、团斑状构造,蚀变以钾化、硅化、绢云母化、绿泥石化为主。岩体与大理岩地层接触带矿体呈透镜状、似层状、巢状、串珠状,矿石主要为致密块状构造、脉状构造,蚀变以钙铝榴石化、透辉石化、透闪石-阳起石化、绿帘石化为主。研究区具有3期成矿作用,分别与二长花岗岩、构造热液活动和闪长岩脉有关,在空间上具有一定程度的叠加。矿床受地层、构造、岩浆作用的多重控制,为斑岩-矽卡岩型金铜矿床,研究成果为区域找矿具有参考和借鉴意义。

The Au-Cu ore deposit Kateba’asu is one of recently discovered large gold-copper deposits in Western Tianshan Mountains in Xinjiang.In this paper,the authors present a research result on geological characteristics,mineral composition and texture&structure of ores,wall-rock alteration,mineralization periods of and the ore-controlling factors of the Kateba’asu ore deposit,The geological,mineralogical and petrological studies of the deposit indicate that ore bodies are mainly occur in the monzogranite,and controlled by both the jointed structural system of fracture zone,and the contact zone of intrusion and marble strata.The ore bodies in jointed system are vein-shaped,with ore structures such as fine veins,veinlets-disseminated,and spotted massive,and the alterations are mainly potash feldspathization,silicification,sericitization and chloritization.Ore bodies in the contact zone of intrusion and marble are lenticular-,stratoid-,nests-,and bead-shapped;ores mainly show massive and vein structure.The altertations are grossularization,diopsidization,tremolite-actinolitization and epidotization.There are two phases of mineralization in the deposit,which are related to monzogranite and diorite-dyke respectively and superposed in space to a certain extent.The deposit is controlled by strata,structure and magmatism,and is the type of Skarn-fracture zone altered deposit.The research results may provide the direction for the regional prospecting.